Keyl C, Lemberger P, Rödig G, Dambacher M, Frey A W
Klinik für Anaesthesiologie, Universität Regensburg, Germany.
J Cardiovasc Risk. 1996 Apr;3(2):221-7.
Periodic fluctuations in respiration such as Cheyne-Stokes respiration or the sleep apnoea syndrome are known to be associated with very-low-frequency oscillations in heart rate (cycle times about 30-120s), which may be related to periodic changes in sympathetic and vagal tone. Since disturbances in cardiac sympathovagal balance have been associated with increased cardiovascular morbidity and mortality, especially in patients with coronary artery disease (CAD), we investigated changes in cardiac autonomic control in patients with CAD during periodic breathing episodes.
Thirty-five patients with a left ventricular ejection fraction (LVEF) of > 50% and 13 patients with an LVEF of < or = 35%, who were scheduled for coronary bypass surgery, were studied using a nocturnal Holter electrocardiograph (ECG) and pulse oximetric recordings. Heart rate variability was assessed by spectral analysis during cyclic oxygen desaturation episodes, indicating periodic breathing patterns, and during control episodes with normal oxygen saturation.
Cyclic oxygen desaturation episodes with a duration of at least 20 min were observed in 17 patients with an LVEF of > 50% and in nine patients with an LVEF of < or = 35% (minimal oxygen saturation 83.9 +/- 3.1 versus 80.4 +/- 5.6%; cycle frequency between 0.0068 and 0.0294 Hz, no significant differences between groups), all of which were associated with very-low-frequency (0.0033-0.04 Hz) oscillations in the heart rate. During cyclic desaturation episodes patients with normal, as well as those with imparied left ventricular function, had marked increases (P < 0.01) in very low frequency power, low frequency (0.04-0.15 Hz) power and the ratio of low-to-high frequency (0.15-0.4 Hz) power. The low:high frequency ratio was significantly higher in patients with an LVEF of > 50% than in patients with an LVEF of < or = 35% during cyclic desaturation episodes, but not during control episodes.
Repetitive oxygen desaturation episodes are associated with marked changes in heart rate variability which indicate cardiac sympathetic predominance in patients with CAD. Our results suggest differences in the modulation of cardiac sympathovagal balance during periodic breathing episodes between patients with normal and imparied left ventricular function.
呼吸的周期性波动，如潮式呼吸或睡眠呼吸暂停综合征，已知与心率的极低频振荡（周期约为30 - 120秒）有关，这可能与交感神经和迷走神经张力的周期性变化有关。由于心脏交感 - 迷走神经平衡紊乱与心血管发病率和死亡率增加有关，尤其是在冠状动脉疾病（CAD）患者中，我们研究了CAD患者在周期性呼吸发作期间心脏自主神经控制的变化。
对35例左心室射血分数（LVEF）> 50%和13例LVEF≤35%且计划进行冠状动脉搭桥手术的患者，使用夜间动态心电图（ECG）和脉搏血氧饱和度记录进行研究。在周期性氧饱和度下降发作（表明周期性呼吸模式）期间以及正常氧饱和度的对照发作期间，通过频谱分析评估心率变异性。
在17例LVEF> 50%的患者和9例LVEF≤35%的患者中观察到持续至少20分钟的周期性氧饱和度下降发作（最低氧饱和度83.9±3.1%对80.4±5.6%；周期频率在0.0068至0.029 Hz之间，两组间无显著差异），所有这些发作均与心率的极低频（0.0033 - 0.04 Hz）振荡有关。在周期性氧饱和度下降发作期间，左心室功能正常以及受损的患者，其极低频功率、低频（0.04 - 0.15 Hz）功率以及低频与高频（0.15 - 0.4 Hz）功率之比均显著增加（P < 0.01）。在周期性氧饱和度下降发作期间，LVEF> 50%的患者的低频与高频功率比显著高于LVEF≤35%的患者，但在对照发作期间并非如此。
重复性氧饱和度下降发作与心率变异性的显著变化有关，这表明CAD患者心脏交感神经占优势。我们的结果表明，左心室功能正常和受损的患者在周期性呼吸发作期间心脏交感 - 迷走神经平衡的调节存在差异。
